Hydroplastic polymers as eco-friendly hydrosetting plastics

Despite the considerable benefits plastics have offered, the current approaches to their production, use and disposal are not sustainable and pose a serious threat to the environment and human health. Eco-friendly processing of plastics could form part of the solutions; however, the technological challenge remains thorny. Here, we report a sustainable hydrosetting method for the processing of a hydroplastic polymer—cellulose cinnamate. Synthesized via facile solvent casting, the transparent cellulose cinnamate membranes are mechanically robust, with tensile strength of 92.4 MPa and Young’s modulus of 2.6 GPa, which exceed those of most common plastics. These bio-based planar membranes can be processed into either two-dimensional (2D) or three-dimensional (3D) shapes by using their hydroplastic properties (using water to manipulate the plasticity). These desired shapes maintain stability for >16 months and can be repeatedly reprogrammed into other 2D/3D shapes, substantially extending their lifetime for practical applications. Eco-friendly processing of plastics could leverage the advantages of plastics while maximizing their environmental sustainability. Here the authors show a cellulose cinnamate polymer that could be repeatedly programmed into various 2D or 3D stable shapes through a sustainable hydrosetting process.